Preparation of polycyclic aromatic compounds



atented ay 7,1946

estate PREPARATION OF POLYCICLIC COMPOUNDS Chester E. Adams, Highland, Ind asslgnor to Standard Oil Company, Chicago, lit, a oorporation of Indiana No Drawing. Application May 29, 1942, Serial No. 445,077

'17 Claims.

The present invention relates to polycyclic aromatic compounds and derivatives thereof and more particularlyto the preparation of polycyclic aromatic alcohols from monoand poiy-haloalkyl substituted polycyclic aromatic hydrocarbons.

In accordance with the present invention a monoor poly-haloalkyl substituted polycyclic aromatic compound is hydrolyzed at an elevated temperature in an aqueous medium or in an aqueous medium containing'a small quantity of a material having an alkaline reaction, to produce the corresponding monohydric or polyhydric polycyclic aromatic alcohol. In addition to monoor poly-haloalkyl substituents the polycyclic aromatic hydrocarbon may contain other aliphatic substituents. The probable reaction mechanism is illustrated by the following "equations in which naphthalene and anthracene are .used for the purpose of villustration, although other polycyclic or condensed ring aromatic hydrocarbons suchas, for example, phenanthrene, can beused.

1 P. I R

7 non a' n Hi0. w EX a ROE l 2H|O +Y2HX ax ROH a i 1 in which R is a bivalent aliphatic-radicalsuch as those derived from methane, ethane. butane,

pentane. hexane. and the like. x is a halogen such as chlorine, bromine, etc. and It represents lwdrogenoroneormorealiphaticradicalssuchas I methyl. ethyl, amyl. etc. WhenR' is an aliphatic cyclic aromatic tor example the dichloromethyl .7 ROB son v r v R, R 211.0 -i m +2 non substituent it may be the same as or different from R.

The haloalkyl substituted polycyclic aromatic compound from which the alcohol is obtained may be, prepared by reacting a polycyclic aromatic hydrocarbon with an aliphatic aldehyde in the presence of hydrochloric acid at an elevated temperatureot from about F. to about 200 F. The aromatic compound maybe naphm thalene, alk'yl substituted naphthalenes, anthraoene, alkyl substituted anthracene, phenanthrene, alkyl substituted phenanthrenes, catalytic reformate polymers, polycyclic hydrocarbons from the "catalytic cracking of hydrocarbons, and other 15 aromatic compounds. "Aliphatic aldehydes such as formaldehyde, paraiormaldehyde, acetaldehyde and the like can be employed. .The reaction if desired can be carried out in a suitable solvent such as a petroleum naphtha;

0 While the monohydric polycyclic aromatic alcohols are obtained from the mono-haloalkyl polycyclic aromatic hydrocarbons, the polyhydric polycyclic aromatic alcohols are obtained from the poly-haloalkyl polycyclic aromatic hydrocar- 2 bone or from the poly-haloalkyl substituted alkyl substituted polycyclic aromatic hydrocarbons. The following example is illustrative of a method of obtaining poly-haloalkylsubstituted alkyl substituted polycyclic aromatic hydrocarbons.

prepared by heating a mixture of 50 grams of beta methyl naphthalene, 31 grams of paraformaldehyde, 10 grams of ZnCh and 100 c. c. of 37% aqueous HCl at F.-.F. for two hours while agitating and passing in a slow stream of H01 gas. The temperature was then raised to 32-175 '1". and held at this temperature for iour hours while passing in a stream of HCl and vigorously stirring the mixture. The mixture was then cooled, extracted with benzene and the benzene layer washed with water until free of acid. The benzene solution was then vacuum distilled until 33 grams or monochloromethyl beta methyl naphthalene distilled over. The residue remaining-in the flaskwas a brown solid which was recrystallized in naphtha to a white crystalline solid'having'a melting point of 205 F.--210 F. and a softening point or about F. The material was dichloromethyl beta methyl naphthalene which had a molecular weight of 238 as determined by the Menzies method.

' Likewise other poly-haloallryl substitutedalkyl substituted polycyclic aromatic hydrocarbons can i be prepared by employing the suitable alkyl poly- Dichloromethyl beta methyl naphthalene was a methyl anthraeene may be obtained by starting may be a mixture of the alcohol and the corre-' sponding ether. Mixtures of alcoholand ether are also obtained when the hydrolysis takes place in alcoholic solutions.

The following examples are illustrative:

Example 1 A mixture of 1 gram of -1-chloromethyl-2- methyl naphthalene, 1 gram of NaHCOa and 800 c. c. of water were refluxed for one hour and filtered hot to remove an undissolved material. The filtrate was then cooled to +40 F. and the white needle shaped crystals of l-methylol 2- methyl naphthalene separated by filtration. A

yield of 0.65 gram (72% of the theoretical) of the product was obtained.

Example 2 One gram of l-chloromethyl 2-methyl naphthalene in 800 c. c. water were refluxed for one hour, filtered while hot and the filtrate cooled to of 280 F. and a found molecular weight of 184 (calc. 188). A yield of 5.9 grams was obtained.

Example 6 A mixture of 2 grams of dichloromethyl beta methyl naphthalene, 2 grams NaHCOz and 300 c. 0. water were heated at refluxing temperature for four hours. The hot solution was then filtered to remove undissolved material and the filtrate evaporated substantially to dryness. The

' residue was then dissolved in 200 c. c. benzene and refluxed for one hour, the hot solution filtered and the filtrate cooled to room temperature. A white crystalline solid was obtained having a melting point of 290 F.-295 F. and a softening point oi about 280 F. The product was dimethylol beta methyl naphthalene and had a molecular weight of 210 as determined by the Menzies method, as compared to a calculated molecular weight of 202 for this compound. The mono and polyhydric aromatic alcohols of the present invention may be employed for many uses. For example, monohydric aromatic alcohols when heated with phthalic and phosphorus acids yield products useful as plasticizers for plastics. The polyhydrlc aromatic alcohols when heated with dibasic acids such as maleic and phthalic acids or their anhydrides yield valuable plastics for coating compounds.

Although the present invention has been described in connection with a specific embodiment thereof, it is to be understood that it is not intended that the same shall be limitative of the scope of "the invention except insofar as included F. A yield of 0.63 gram (70% of the theoretical) of l-methylol 2-methyl naphthalene was obtained.

Example 3 Two 5 gram portions of l-chloromethyl 2- methyl naphthalene were added ina boiling solution of 10 grams of NaHCOa in 150 c. c. ethyl alcohol, 150 c. 0. water at 15 minute intervals and refluxed for one hour. The mixture was then cooled, diluted with 1000 c. 0. water and precipitated l-methylol 2-methyl naphthalene filtered off. A yield of 7 grams (78% of the theoretical). was obtained.

Example 4 A mixture of 2.5 grams of l-chloromethyl 2- methyl naphthalene, 1 gram NaOH, c. c. ace- Example 5 A mixture 01' 10 grams of l-chloromethyl 5- chloromethyl naphthalene, 1 gram NaaCOJ' and 350 c. 0. water was refluxed one-half hour and filtered while hot to remove undissolved solids.

The solid was then added to a fresh portion of 350 c. 0. water containing 1 gram NaHCOy, themixture refluxed for another one-half hour and filtered while hot to remove undissolved solids. This procedure was repeated five times. The combined filtrates were reduced to a volume of 200 c. c., cooled, and'1.5-dimethylol naphthalene separated, as a white crystalline solid having a melting point 0! 310 l t-315 F, a softening point. B

in the accompanying claims.

I claim:

l. The method 01. preparing a polycyclic aromatic alcohol comprising mixing an haloalkyl substituted polycyclic aromatic compound with a hydrolyzing agent selected from the group consisting of water and a sufllciently dilute alkaline aqueous solution to dissolve substantially all of the alcohol formed, heating the mixture and subsequently recovering the resulting polycyclic aromatic alcohol. Y

2. The method of claim 1 in which the haloalkyl substituted polycyclic aromatic compound is an haloalkyl substituted naphthalene.

3. The method of claim 1 in which the haloalkyl substituted polycyclic aromatic compound is a chloroalkyl naphthalene.

4. The method oi claim 1 in which the haloalkyl substituted polycyclic aromatic compound is a bromoalkyl naphthalene.

5. The method 01' claim 1 in which the haloalkyl substituted polycyclic aromatic compound is achloromethyl naphthalene.

6. The method or preparing an alkyl-substituted polycyclic aromatic alcohol comprising mixing a haloalkyl substituted alkyl-substituted polycyclic aromatic compound with a hydrolyzing agent selected from the group consisting of water and a sufilciently dilute alkaline aqueous solution to dissolve substantially all of the alcohol formed, heating the mixture and subsequently recovering the resulting alkyl-substituted polycyclic aromatic alcohol.

7. The method of preparing an alkyl-substituted monohydric aromatic alcohol comprising mixing a monohaloalkyl-substituted alkyl-substituted polycyclic aromatic compound with a hydrolyzing agent selected from the group consisting of water and a sufiiciently dilute alkaline aqueous solution to dissolve substantially all of the alcohol formed. heating the mixture and subsequently rea I I asoome covering the chi-substituted monohydric polycyclic aromatic alcohol.

8. The method or preparing a monomethylol alkyl-substltuted polycyclic aromatic compound comprising heating a chloromethyl-alkyl-substituted polycyclic aromatic compound in a suinciently dilute alkaline aqueous solution to disis. The method or preparing an alkyl-substituted polycyclic aromatic dihydric alcoho1 comprising mixing a dihaloalkyl' substituted alkyisubstituted polycyclic aromatic compound with an aqueous solution or an alkaline reagent sufilciently diluted to dissolve substantially all of l the alkyd-substituted polycyclic aromatic dihydric solve substantially all of the mono-methylolalkyl-substituted polycyclic aromatic compound formed, cooling the mixture to precipitate the "methylol alkyl-substitu'ted polycyclic aromatic compound, and subsequently removingthe same from the supernatant-liquid.

9. The method of preparing methylol methyl naphthalene comprising heating. a chloromethyl methyl naphthalene with a suiiiciently dilute alkaline aqueous solution to dissolve substantially all of the methylol methyl naphthalene formed, filtering the hot mixture to remove undi'ssolved material therefrom, cooling the nitrate, to precipitate the methylol methyl naphthalene, and

alcohol iormed, heating the mixture and subsequently recovering the alkyl-substituted polypound with a sumciently dilute aqueous solution of an alkaline reagent to dissolve substantially all or the polycyclic aromatic dihydric alcohol formed, heating the mixture and subsequently recovering the alkyl-substituted polycyclic aromatic dihydric alcohol.

recovering the precipitated methylol methyl naphthalene.

- 10. The method or preparing methylol methyl naphthalene comprising heating chloromethylmethyl naphthalene with water,- illteringthe hot mixizire to remove undissolved material thereiron'i. cooling the-filtrate to precipitate the methylol methyl naphthalene and recoveringthe' precipitated methylol methyl naphthalene.

11. The method of preparing a polycyclic. am-

matic polyhydrlc alcohol comprising mixing a poly haloalkyl substituted polycyclic aromatic compound with a hydrolyaingagent selected from the group consisting, of water and a suiiiciently dflute alkaline aqueous solution to dissolve substantially all or the polycyclic aromatic polyhydric alcohol i'crmed, heating the mixture and subsequently recoveringthe polycyclic aromatic polyhydric alcohol formed. 1 Y 12. The method described-in claim 11 in which the mixture is-heated at-a temperature within the range of about 100 1". to about 850' I";

.15. The method oi preparing a dimethylol,

alkyl substituted polycyclic aromatic compound comprising heating a ,dichloromethyl alk'yl-sub stituted polycyclic aromatic compound in a sufllciently dilute aqueous solution of an alkaline reagent to dissolve substantially all of the dimethylol alkyl-substituted polycyclic aromatic compound formed, coolingthemixture to precipitate the dimethyiol alkylqsubstituted poly-l A cyclic aromatic compound and subsequently removing the same from the supernatant liquid.

16. The preparation '6! .dimethylol methyl naphthalene comprising heating dichloromethyl methyl naphthalene with water, filtering the hot mixture to remove undissolved material thereirom, cooling the filtrate ,to' precipitate dimethylol methyl naphthalene and recovering the l precipitated dimethylol naphthalene.

17. As a new composition or matter dimethylol methyl-naphthalene. I CHESTER E. ADAMS. 

